When does it get better?

I know it's early days as my lo is only 18 days old but I'm already exhausted and wondering when it gets better?
He's at that stage where he just wants to feed all the time - I know he'll become more efficient at it eventually but can't for the life of me remember how long this stage lasts.
He also gets bad bouts of colic - usually late in the evening but at times it lasts literally all night and I'm up until 3 or 4 in the morning with him. The only way he'll settle on these nights is if I keep him in bed with me after he's had a feed and hubby gets banished to the spare room. Nothing against co-sleeping, but it's not for me and I'm not sure how i've ended up doing it!! I can't relax when he's in bed with me and I don't get a proper sleep, but if we didn't do this the alternative is rocking him until that time of the morning and then I'd get no sleep at all! Other mornings he's up from 3 or 4 and doesn't go to sleep until 6am by which point it's only half an hour until ds1 gets up for the day so essentially my day is lasting from that time of the morning until maybe 9 or 10 at night until hubby gets in from work and takes over for an hour or two. His colic also seems to be worse when i eat fruit or veg so i'm almost avoiding these foods which I know is ridiculous as I'm getting really run down already but I don't want to do anything that's going to make my baby's pain worse.
I'm using the granules for colic and cluster feeding in the evening to see if he needs less milk at night but other than this i don't know how I can make things better for all of us.
I know things will improve and I just have to survive ths bit, but I was hoping someone could tell me when their baby got over the worst of the colic and got into a better night time routine. ds1 is only 2 and a half but already this stage of his life is a distant memory and I can't remember when it all fell into place.